This invention relates to analog-to-digital converters. More particularly, it is concerned with analog-to-digital converting apparatus controlled by a microprocessor.
In many control systems which operate with data in digital form, specifically microprocessor systems, a large amount of data is obtained in analog form and must be converted to digital form before processing. For analog-to-digital converting apparatus having a large number of analog inputs it has been conventional to multiplex the analog inputs into the converting apparatus. With this technique, however, analog voltages must be conducted through many noise sensitive lines decreasing the accuracy of the received data. In addition, there are problems in expanding the number of analog inputs into the system.